Establishment of identification database of six common dermatophytes using Biolog automatic analyzer for microbes

Abstract

Objective To investigate the application prospect of Biolog automatic analyzer for microbes in the identification of common dermatophytes. Methods Clinical isolates of dermatophyte were identified to species level based on phenotypes and DNA sequence. The strains of Trichophyton rubrum, Trichophyton mentagrophyte, Trichophyton tonsurans, Microsporum canis, Microsporum gypseum and Epidermophyton floccosum were inoculated into FF microplates, and the utilization of 95 different carbon sources were recorded.The growth and reaction spectrum of these strains were described and identification database was set up. Results There was a great difference in the utilization of carbon sources among different fungal species. The utilization of raffinose could differentiate Trichophyton mentagrophyte and Trichophyton tonsurans from the other four Trichophyton. Sebacic acid could differentiate Trichophyton mentagrophyte from Trichophyton tonsurans.Meanwhile, Trichophyton rubrum could be differentiated from Microsporum gypseum, Epidermophyton floccosum and Microsporum canis by utilization of fumarate and succinate. Microsporum gypseum could be identified by use of alanine and phenylalanine. The utilization of dextrin could distinguish Epidermophyton floccosum from Microsporum canis. Conclusion The Biolog automatic analyzer for microbes has the ability to identify common dermatophytes to species level based on their specific phenotype. Key words: Dermatophytes;  Biological assay;  Autoanalysis;  Databases